In the field of medicine, implants are often used that are introduced into an animal and/or human body either permanently or at least for a relatively long period of time in order to carry out replacement functions. For example, these implants could include heart pacemakers, brain pacemakers for Parkinson's patients, cardiac implants, cochlear implants, retinal implants, dental implants, implants for joint replacement, vessel prostheses, or stents.
Implants are connected to catheters for insertion into the body and have to be able to be placed precisely at the site for use and released in a controlled manner. An example technique to release the implant is by a sliding motion.
Known catheters are sized according to a dependent relationship between the overall length of the catheter and the length of the implant, for example of a stent. The longer is the stent, the longer is the overall length of the catheter. Thus, the overall length for a catheter for insertion of a stent 200 mm long is at least 180 mm longer than the same catheter with a stent 20 mm long. This impairs the release of the implant at the intended site.
For the doctor, this necessitates use of a longer guide wire, which, when releasing the implant, leads to a longer path of displacement of the catheter over the guide wire and to complicated handling. From an ergonomic point of view the handling of such a long system is awkward for the user. The user requires both hands to release the implant using a release device known as the “pull-back system” provided for this purpose.
A release system for a long stent is known from EP 1 844 739 A1 and has a short handle. In order to release the stent in the site for use, an outer shaft is retracted, wherein it is led away by a branch from the handle.